With the help of Moulded Interconnect Device technology, MID for short, three-dimensional circuit traces can be applied on the surface of injection moulded components. This enables mechanical and electronic functions to be integrated on a single moulded part in a unique way. The products can therefore be designed much more freely in terms of space and made much smaller and lighter. At the same time, MID components often make do completely without cables, which makes them much easier to assemble.
Unlike classic predominantly two-dimensional printed circuit boards, MID technology uses a three-dimensional shaped part as a circuit board, for example the housing. There are various production methods for making MIDs. In the case of the frequently used Laser Direct Structuring (LDS), a special metal connection (catalyst) is added to the injection moulding plastic.
The required component is first moulded from this material. The areas where circuit traces are planned are then exposed with a laser beam. At the same time the added metal connection is activated and can be immersed in a copper bath, for example, during the subsequent metallisation process, whereby the circuit traces are formed with a sharp outline. Various coatings made of copper, nickel or gold can thus be applied one after the other. Electric circuits can be soldered onto the resulting conductive areas.
Explaining video for the process's steps:
Eng. Rami Khalil
Mechanical Design and Production Engineer.